When yarn is to be dyed in package form it is necessary to support the yarn packages on some form of perforated or permeable core for the dyeing operation. Sometimes this is done by arranging the packages directly on the spindles of the package dyeing equipment, but for the most part special dye cores are used to support each package before placing them on the dye machine spindles. A variety of dye core forms are employed among which are the so-called dye springs consisting of spiral stainless steel springs perferably having the coils laced in a manner allowing spring compression while controlling maximum spring length. Perforated or slotted tubes of stainless steel, plastic or fortified paperboard are also used.
It is possible to wind yarn onto the dye cores in forming the packages for dyeing, but if this is done it either involves an extra winding operation in preparation for dyeing or it requires that a substantially greater number of the relatively expensive dye cores be provided to accommodate the yarn package inventory normally maintained to supply the dyeing operation. Accordingly, it is common practice to wind the supply packages on inexpensive paper or plastic core tubes and then transfer them to dye cores, without rewinding, in preparation for dyeing so that dye cores are used only during the package dyeing and subsequent drying and off-winding operations and no more are required than is needed to service these operations.
Such transfer is effected by displacing the core tube axially from the yarn package wound thereon while replacing it with a dye core. To facilitate this transfer operation it is customary to employ a core tube initially that is diametrically sized somewhat larger than the dye core that is to replace it for dyeing. This practice also has the advantage of relaxing winding tension adjacent the package center by allowing some contraction onto the dye core, and such contraction is particularly helpful when textured yarns or the like are being handled, as noted in U.S. Pat. No. 3,425,110 which illustrates a package transfer operation of a sort that has been common according to prior practice.
The general trend in equipment for performing the transfer step has been to provide for automatic operation and a number of troublesome problems have been encountered in using such equipment. To begin with, the core tubes employed for winding cannot be depended on for entire dimensional consistency in diameter or length, nor are the yarn packages always correctly positioned on the core tubes by the winding operation, and the result of such imperfections has often been damage to the core tube or transfer failure, either of which results is likely to be accompanied by yarn loss or equipment damage through jamming or both. Comparable problems and results have been encountered because of damage to the projecting ends of the core tubes during handling of the yarn packages after winding until the time comes to prepare them for dyeing, or because of inability of automatic mechanisms to deal acceptably with the core tube dimensional variations that must be expected, or because of difficulties in locating the core tubes accurately enough for proper mechanical mating with the transfer mechanisms. In addition, there have been considerable problems involved in assuring a proper replacement location of the dye cores in the absence of which the integrity of the transferred yarn package is apt to be lost.
Such difficulties are eliminated according to the present invention by a procedure and enabling means that utilizes a significant degree of manual manipulation in a manner that equals or improves the handling rates possible with automatic mechanisms heretofore in use.